The present invention generally relates to reducing power consumption in a communication device. More particularly, the present invention relates to power management in a portable radiotelephone.
Many communication devices operate on battery power. The radiotelephones in use today are almost all portable devices utilizing batteries that need periodic recharging. The size of the battery and the power efficiency of the communication device determine the amount of talk time available to a user. As a convenience to a user, it has always been desirable to extend the life of the battery to provide longer talk times. However, even with the present devices, communications are occasionally interrupted, requiring the recharging of the battery or replacement with a freshly recharged battery.
Moreover, new phone features and standards are dramatically elevating phone functions, which increase processing power requirements. Such new features and functions include Internet browser capability, wireless multimedia, smart phones and videophones, for example. These requirements also increase processing speed, which is known to increase current drain. High speed packet data, data and image processing, General Packet Radio Service, Global Positioning System service, local connectivity services to a computer or peripherals, multimedia cards, and multiple high processing functions all require an increased level of processor operational speed, hardware accelerators, more complicated hardware and software, larger and more complicated instruction sets. Further, the phone may be called upon to power additional phone modules that plug into the phone.
As a result, the operational frequency of the phone processor has increased and the number of transistors on the phone IC sets has increased to support these new functions and interfaces. Modern silicon technology has been improving, but has not kept pace with the functional revolution in phone technology. Consequently, the power demands on a phone has been constantly increasing. Therefore, it has been desirable to further extend the battery life on a communication device.
At the same time, there are limiting factors in the phone themselves. New phones must be as small or smaller than the phones they are replacing. Therefore, batteries must be smaller. In addition, the amount of power dissipation is limited by the smaller package, existing silicon technology, and the temperature limits of components in the phone. Further, the battery technology is not able to provide the necessary current for a sufficient time in some of the desirable or simultaneous user modes. For example, a wireless packet data connection in GPRS for an Internet browser, or local connectivity to a computer and multimedia functions, would have a high current drain on a battery.
There are several existing power management techniques to reduce power consumption of phone circuits and processors. These techniques include (US patent class 713/320) lowering voltage, frequency modulation, lowering frequency, gating clocks and/or transmitter/receiver, shutdown components in the phone that are not being used at the time (standby/sleep mode), etc. However, these techniques are reactive in that they will still provide full operability of the phone even though the battery may not be able to supply sufficient power for all functions.
Accordingly, there is a need for a method and apparatus for predictive current reduction and extension of a battery lifetime in a communication device such as a radiotelephone. There is a further need to provide user input and options as to the operability of particular functions of the phone. It would also be of benefit to provide these advantages without additional hardware, which would increase the cost of the communication device.